Hair conditioning compositions are typically applied to the hair immediately after shampooing and rinsing the hair. The conditioning composition is worked through the hair, and may then be left to penetrate the hair for a period of time before rinsing it from the hair with water.
Traditionally such conditioning compositions have used a combination of cationic surfactants and fatty materials, typically long chain fatty alcohols. This combination forms a lamellar gel phase which imparts a desirable viscosity to the product and deposits on the hair during use of the product to provide a conditioning benefit.
Many consumers desire a “lighter” conditioning product which imparts less of a slippery and coated feel to their hair. This has led to the development of “low-fat” formulations with a reduced content of fatty material.
However, reducing the content of fatty material can also reduce the viscosity of the product to an unacceptable level. Consequently, it has been found to be necessary to incorporate a thickener.
Examples of thickeners which have been used for this purpose are nonionic cellulose ethers such as hydroxyethylcellulose.
Hydrophobically-modified cellulose ethers such as cetyl hydroxyethylcellulose have also been used. Materials of this type are described in EP 412 705, EP 412 706 and EP 412 710 as providing a rheology very much like the gel-network structure of typical hair conditioners without the slimy feel associated with most polymeric thickeners, and without using a typical quaternary ammonium compound/fatty alcohol gel-network thickening system.
A problem associated with hair conditioning compositions such as those described above is that it is difficult to obtain the right viscosity profile under different conditions of product usage. For example, a thick, creamy product viscosity is desirable to enable controlled pouring and product dosage onto the hair. However, in order to facilitate spreading of the product through the hair and rinsing, it is desirable that the product viscosity breaks down rapidly on dilution. If the product is difficult to rinse from the hair, then this may contribute to sensory negatives perceived by the consumer such as a dirty, “coated” hair feel after use.
The inventors have found that this problem can be solved by incorporating a fatty acid and a water-soluble, nonionic polymer of alkylene oxide into the hair conditioning composition.
JP2002226327 describes a hair cosmetic which is readily pourable, which has a rich product feel on the hand, and which provides a smooth hair feel after rinsing and drying. The cosmetic incorporates a higher fatty acid having a hydroxyl group in a side chain, such as 12-hydroxystearic acid.
DE19641841 describes an aqueous composition comprising 10 to 26 C fatty acid, in combination with directly acting hair dye and certain alcohol or glycol ether solvents. The composition is said to provide good conditioning and hair dyeing effects.
WO99/44568 relates to the use of water-soluble nonionic polyethyleneoxide homopolymers to increase hair body and fullness when formulated in a high pH medium and applied to fine hair. They are said to deposit under the hair cuticle and provide it with more surface roughness and texture.
WO95/20939 describes thickened cream rinse emulsions with a combination of low melting point fatty alcohol with polyethyleneoxide homopolymers. The emulsions are said to provide excellent wet hair feel, spreadability, and rinseability, as well as providing glossiness, hair alignment, and volume reduction, and especially dry combing benefits.